POS0707 EFFECTIVENESS AND SAFETY OF INTRAVENOUS VERSUS SUBCUTANEOUS TOCILIZUMAB IN TAKAYASU ARTERITIS: MULTICENTER RETROSPECTIVE STUDY
Authors: A. Mekinian, D. Saadoun
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Recently, the effectiveness of biological therapies such as inhibitors of tumor necrosis factor-α (TNF-α) and IL-6 receptor (tocilizumab) in TAK patients who were refractory to other immunosuppressive therapies has been reported in several studies. We have recently reported a French nationwide registry that showed quite similar effectiveness of TNF-α antagonists and tocilizumab, with acceptable safety profile and significant steroid sparing effect. A recent phase 3, randomized, double blind, placebo-controlled trial of tocilizumab <i>versus</i> placebo in TAK failed to reach its primary intention-to-treat analysis, but tocilizumab was favored in a secondary per-protocol analysis regarding TAK time to relapse. Besides its role on refractory patients, intravenous tocilizumab was also evaluated in treatment-naïve TAK patients in the French TOCITAKA prospective multicenter open-labeled trial, showing 6-month remission rates of 80%, of whom 54% were in glucocorticoid-free remission at 6 months. <h3>Objectives</h3> In this large multicenter study, we compared the effectiveness and safety of tocilizumab IV <i>versus</i> SC in 109 TAK patients. <h3>Methods</h3> We conducted a retrospective multicenter study in referral centers from France, Italy, Spain, Armenia, Israel, Japan, Tunisia, and Russia regarding biological-targeted therapies in TAK, since January 2017 to September 2019. <h3>Results</h3> A total of 109 TAK patients received at least 3 months tocilizumab therapy and were included in this study. Among them, 91 and 18 patients received IV and SC tocilizumab, respectively. A complete response (NIH&lt;2 with less than 7.5 mg/day of prednisone) at 6 months was evidenced in 69% of TAK patients, of whom 57 (70%) and 11 (69%) patients were on IV and SC tocilizumab, respectively (p=0.95). The factors associated with complete response to tocilizumab at 6 months in multivariate analysis, only age &lt; 30 years (OR = 2.85, 95% CI 1.14; 7.12; p=0.027) and time between TAK diagnosis and tocilizumab initiation (OR = 1.18, 95% CI 1.02; 1.36; p=0.034). During the median follow-up of 30.1 months [0.4; 105.8] and 10.8 [0.1; 46.4] (p&lt;0.0001) in patients who received tocilizumab in IV and SC forms, respectively, the risk of relapse was significantly higher in TAK patients on SC tocilizumab (HR = 2.55, 95%CI 1.08;6.02; p=0.033). The overall cumulative incidence of relapse at 12 months in TAK patients was at 13.7% (95%CI 7.6; 21.5), with 10.3% (95%CI 4.8;18.4) for those on IV tocilizumab <i>versus</i> 30.9% (95%CI 10.5;54.2) for patients receiving SC tocilizumab. Adverse events occurred in 14 (15%) patients on IV route and in 2 (11%) on SC tocilizumab. <h3>Conclusion</h3> In this study, we confirm that tocilizumab is effective in TAK, with complete remission being achieving by 70% of DMARDs-refractory TAK patients at 6 months. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.